SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Zhu Han,Danyang Nan,Huan Yang,Qianqian Sun,Shuang Pan,Hui Liu,Xiaoli Hu
A novel method was established for the ratiometric fluorescence detection of Cu 2+ and glutathione (GSH) by carbon quantum dots (CQDs), and it was fabricated through one-pot facile hydrothermal treatment using o-phenylenediamine (OPD) and citric acid as precursors. Based on the selective oxidation reaction of OPD with Cu 2+ , the detection strategy of Cu 2+ was proposed using ratiometric fluorescence probe. The oxidation production (2,3-diaminophenazine) of OPD, obtained through the oxidation reaction of OPD and Cu 2+ , not only emerged a new emission peak at 562 nm, but also quenched the fluorescence of CQDs with maximum emission at 446 nm. The mechanism was Förster resonance energy transfer (FRET) between CQDs and 2,3-diaminophenazine (oxOPD). Furthermore, the oxidation reaction between Cu 2+ and OPD could be inhibited when added GSH into the solution, which could prevent the fluorescence of CQDs being quenched. The sensing system showed high sensitivity toward Cu 2+ and GSH in a range of 0.25–10.0 μmol L −1 and 1.0–80.0 μmol L −1 with a detection limit 0.076 μmol L −1 and 0.30 μmol L −1 , respectively. Besides, the proposed method could apply to efficient quantification of Cu 2+ and GSH in practical samples.
研究领域:
分析化学
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生物医学
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DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Liang Wu,Qing-Sheng Guo,Yu-Qian Liu,Qing-Jiang Sun
In this work, we report the design and application of a new ratiometric fluorescent probe, which contains different-colored quantum dots (QDs) as dual fluorophores, ultrathin silica shell as spacer, and meso-tetra(4-sulfonatophenyl)porphine dihydrochloride (TSPP) as receptor, for Zn2+ detection in aqueous solution and living cells. In the architecture of our designed probe, the silica shell plays the key roles in controlling the locations of QDs, TSPP, and Zn2+, preventing the direct contact between QDs and Zn2+ but affording fluorescence resonance energy transfer (FRET) from dual-color QDs to TSPP. In the presence of Zn2+, the analyte-receptor reaction changes the absorption in the range of the Q-band of TSPP and accordingly the efficiencies of two independent FRET processes from the dual-colored QDs to the acceptor, respectively, leading to fluorescence enhancement of green-emission QDs whereas fluorescence quenching of yellow-emission QDs. Benefiting from the well-resolved dual emissions from different-colored QDs and the large range of emission ratios, the probe solution displays continuous color changes from yellow to green, which can be clearly observed by the naked eye. Under physiological conditions, the probe exhibits a stable response for Zn2+ from 0.3 to 6 μM, with a detection limit of 60 nM in aqueous solutions. With respect to single-emission probes, this ratiometric probe has demonstrated to feature excellent selectivity for Zn2+ over other physiologically important cations such as Fe3+ and Cu2+. It has been preliminarily used for ratiometric imaging of Zn2+ in living cells with satisfying resolution.
研究领域:
生物化学
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分析化学
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材料科学
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DOI
PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2025
·
IF 3.1
Dong Xuemei,Hu Zhongfei,Xiao Xuan,Zhang Keying,Ding Yujie
Excessive Cu 2+ levels pose severe threats to human health and ecosystems, necessitating sensitive and selective detection methods. A novel ratiometric fluorescent probe (CDs@RBH) based on fluorescence resonance energy transfer (FRET) was developed through electrostatic assembly. This nanoplatform employs carbon quantum dots (CDs) as the energy donor and rhodamine hydrazide (RBH) as the acceptor. Upon Cu 2+ addition, the spirolactam ring of RBH opens, triggering a distinct UV–Vis absorption peak at 550 nm, which overlaps with the emission spectrum of CDs (450 nm), enhancing FRET efficiency. This mechanism enables dual-signal readout: the fluorescence intensity of CDs at 450 nm decreases, while the RBH-Cu 2+ emission at 575 nm increases, allowing for precise ratiometric detection. The probe exhibits high selectivity and exceptional sensitivity, with a detection limit (LOD) of 0.65 μM and quantification limit (LOQ) of 2.09 μM. Practical applications in tap water samples demonstrate excellent recovery rates (96–108%). This work presents a straightforward synthesis method, environmental stability, and dual-channel signal verification for detection, making it a promising tool for real-world Cu 2+ monitoring in environmental and biological systems.
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高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 33
·期 8
·085702
·
IF 3.874
Bo Liu,Kun Yang,Siyu Lu,Junjie Cai,Fan Li,Feng Tian
A novel method for the detection of procalcitonin in a homogeneous system by matched carbon dots (CDs) labeled immunoprobes was proposed based on the principle of FRET and double antibody sandwich method. Blue-emitting carbon dots with a strong fluorescence emission range of 400–550 nm and red-emitting carbon dots with the best excitation range of 410–550 nm were prepared before they reacted with procalcitonin protoclone antibody pairs to form immunoprobes. According to the principles of FRET, blue-emitting carbon dots were selected as the energy donor and red-emitting carbon dots as the energy receptor. The external light source excitation (310 nm) could only cause weak luminescence of CDs. However, once procalcitonin was added, procalcitonin and antibodies would be combined with each other quickly (≤20 min). Here, blue-emitting carbon dots acquired energy could be transferred to red-emitting carbon dots efficiently, causing the emitted fluorescence enhancement of red-emitting carbon dots. The fluorescence detection results in PBS buffer solution and diluted rabbit blood serum showed that the fluorescence intensity variation was linear with the concentration of procalcitonin. There was a good linear relationship between F/F0 and procalcitonin concentrations in PBS buffer solution that ranged from 0 to 100 ng ml−1, and the linear equation was F/F0 = 0.004 * Cpct + 0.98359. Detection in the diluted rabbit serum led to the results that were linear in two concentration ranges, including 0–40 ng ml−1 and 40–100 ng ml−1, and the detection limit based on 3σ K−1 was 0.52 ng ml−1. It is likely that this matched CDs labeled immunoprobes system can provide a new mode for rapid homogeneous detection of disease markers.
研究领域:
生物医学工程
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分析化学
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免疫学
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DOI
PubMed
高影响因子
TALANTA
·
2020
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IF 5.339
Zhixia Yao,Hanmeng Liu,Yaosheng Liu,Yongxing Diao,Guangxing Hu,Qifang Zhang,Zhuang Li
A novel fluorometric strategy is proposed for detecting curcumin by polyvinyl pyrrolidone-templated Cu NCs (PVP–Cu NCs) as a fluorescent probe which exhibits excitation/emission peaks at 380/510 nm. The fluorescent excitation and emission spectra of PVP-Cu NCs have a striking overlap with the UV–vis spectrum of curcumin, and the fluorescence lifetime of PVP-Cu NCs decreases after the addition of curcumin. Curcumin leads to fluorescence quenching based on fluorescence resonance energy transfer . This method allows for the determination of curcumin in the range of 0.1–10 μg mL −1 and the detection limit is 21 ng mL −1 . Furthermore, this method displays good selectivity and is successfully applied for real sample analysis.
研究领域:
分析化学
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生物化学
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DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2020
·
IF 10.257
Xixia Liu,Yaoyao Hou,Sirui Chen,Juewen Liu
Dopamine is one of the most important neurotransmitters . A high-quality DNA aptamer for dopamine was reported in 2018. However, fundamental understanding of its binding and folding is lacking, which is critical for related biosensor design. Herein, we performed careful assays using a label-free technique called isothermal titration calorimetry (ITC) to study its secondary structure . We divided this aptamer into four regions and individually examined each of them. We confirmed two stems, but the third stem is believed to be part of a loop. The aptamer was then truncated. The original aptamer had a K d of 2.2 ± 0.3 μM at 25 °C. Shortening the structure by one or two base pairs increased the K d to 6.9 and 44.4 μM, respectively. Dopamine binding was promoted by both increasing the Mg 2+ concentration and decreasing the temperature. At 5 °C, a K d of 0.4 μM was achieved. Based on this understanding, we designed two fluorescence resonance energy transfer (FRET) quenching biosensors that differ only by a base pair. The shorter sensor had 3-fold higher sensitivity and a detection limit of 0.9 μM. In 1% fetal bovine serum, the sensor retained a similar limit of detection of 1.14 μM. A two-fluorophore ratiometric FRET sensor was also demonstrated with a low detection limit of 0.12 μM. This work indicated the feasibility of designing folding-based sensors for dopamine, and this design can be extended to other sensing modalities such as electrochemistry and colorimetry .
研究领域:
分析化学
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生物化学
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生物物理
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神经科学
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分子生物学
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DOI
PubMed
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2025
·
IF 4.6
Zuyao Fu,Ze Chen,Lingfeng Yang,Hao Wang,Jing Xie,Zhaoyang Ding
The misuse of malachite green (MG) has led to significant water pollution, and its metabolite, leucomalachite green (LMG), poses a serious health risk. Rapid detection of drug residues in aquaculture is crucial for food safety. In this study, the dual-emission fluorescent sensor RhB@Tb-MOF (RhB = Rhodamine B) was synthesized based on fluorescence resonance energy transfer (FRET). MG significantly quenches the fluorescence of RhB and affects the fluorescence of Tb-MOF to different extents, making it a suitable ratiometric fluorescent sensor for sensitive MG detection with a limit of detection (LOD) of 9.6 × 10 −3 μg/mL. Although LMG did not affect the fluorescence of RhB@Tb-MOF, it formed a ratio with the fluorescence of RhB@Tb-MOF due to its intrinsic fluorescence properties, and the LOD was 3.5 × 10 −3 μg/mL. Additionally, increasing MG concentrations shifted the sensing system's color from pink to blue, with a colorimetric LOD of 0.15 μg/mL. This paper introduced a colorimetric/fluorescent dual-mode sensor for MG and LMG detection. Furthermore, this sensor was combined with smart labeling technology to achieve rapid on-site quantification of MG, offering significant potential for broad application.
研究领域:
食品安全
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分析化学
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环境科学
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DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2017
·
IF 6.32
Weiqiang Yang,Jiancong Ni,Fang Luo,Wen Weng,Qiaohua Wei,Zhenyu Lin,Guonan Chen
Carbon dots (CDs) emerge as excellent fluorescent nanomaterials, but the full exploitation and application of their exceptional properties in the development of fluorescence assay are still rare. In this work, cationic carbon dots (C-CDs) covered with plenty of positive charges on the surface were synthesized through a facile ultrasonic method. Negatively charged hyaluronic acid (HA) caused the aggregation of positively charged C-CDs and neutral red (NR) along its linear chain via electrostatic adsorption, leading to a remarkable Förster resonance energy transfer (FRET) from C-CDs to NR. However, the presence of hyaluronidase (HAase) resulted in the enzymolysis of HA, as well as the liberation of C-CDs and NR. The corresponding change of fluorescence color from red to green-yellow afforded a reliable ratiometric assay for HAase. Also the ratio of fluorescence intensity for C-CDs (I525) to that for NR (I630) was used for quantitative detection of HAase. The proposed sensing system was easily operated in aqueous media with a detection limit of 0.05 U/mL. This strategy provides a new approach for the wider application of some special CDs in detecting biomolecules.
研究领域:
生物化学
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分析化学
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DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2018
·
IF 4.484
Ying-Ying Wang,Xun Xiang,Ren Yan,Yi Liu,Feng-Lei Jiang
Förster resonance energy transfer (FRET) has attracted much attention for its wide applications in the fields of bioimaging, bioanalysis, etc. One of the critical problems in FRET is the construction of suitable donor–acceptor pair. The fluorescent quantum dots (QDs) can well meet the requirements both for a donor and an acceptor, owing to their tunable emission and broad absorption. Besides, the QDs possess high quantum yield, which highly benefits the FRET efficiency. In this work, glutathione-capped CdTe QDs (GSH-CdTe QDs) was chosen as the energy donor (D) and Rhodamine B (RhB) as the energy acceptor (A). However, no FRET occurred when there were only QDs and RhB, even though there was much overlap between the absorption spectrum of RhB and the emission spectrum of QDs. Interestingly, after the addition of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), FRET was induced favorably. Further understanding of this phenomenon was studied by fluorescence spectroscopy, dynamic light scattering, and zeta potential. The results indicated that QDs aggregated and were cross-linked by CTAB due to electrostatic interactions. Then, RhB was trapped in the aggregates. Therefore, QDs and RhB were pulled closer to a reasonable distance and FRET happened prosperously. Notably, thermodynamics in this process was well studied for an in-depth understanding. This work will render the better design of donor–acceptor pairs to overcome the long distances as well as the deep understanding of FRET with spreading applications.
研究领域:
生物成像
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生物分析
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物理化学
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DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2020
·Vol. 26
·期 57
·13022-13030
·
IF 4.857
Changren Liu,Ling'e Zhang,Sensen Zhou,Xiaoke Zhang,Wei Wu,Xiqun Jiang
Graphical Reductive response : A dendron-based fluorescence turn-on probe mediated by the Förster resonance energy transfer (FRET) mechanism is synthesized by conjugating one Cy5.5 molecule to the focal of a G3 dendron and eight Black Hole Quencher 3 (BHQ-3) molecules to its periphery through a reductively cleavable disulfide linkage. The fluorescence of the probe can be activated effectively and rapidly in the reductive environment of tumors. Specifically amplifying the emission signals of optical probes in tumors is an effective way to improve the tumor-imaging sensitivity and contrast. In this paper, the first case of dendron-based fluorescence turn-on probes mediated by a Förster resonance energy transfer (FRET) mechanism is reported. Dendrons up to the fourth generation with a hydrophilic oligo(ethylene glycol) scaffold are synthesized by a solid-phase synthesis strategy, and show precise and defect-free chemical structures. To construct the fluorescence turn-on probe, one Cy5.5 molecule is conjugated to the focal of a G3 dendron through a robust linkage and eight Black Hole Quencher 3 (BHQ-3) molecules are conjugated to its periphery through a PEG chain bearing a reductively cleavable disulfide linkage. By in vitro and in vivo experiments, it is demonstrated that the fluorescence of the dendron-based probe can be activated effectively and rapidly in the reductive environments of tumor cells and tissues, and the probe thus exhibits amplified tumor signals and weak normal tissue signals. Compared with the reported nanoscale turn-on probes, the dendron-based probe has several significant advantages, such as well-defined chemical structure, precisely controllable fluorophore/quencher conjugation sites and ratio, desirable chemical stability, and reproducible pharmacokinetic and pharmacological profiles, and is very promising in tumor detection.
研究领域:
生物化学
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医学影像
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分子生物学
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PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 43
·期 3
·1424-1430
·
IF 3.201
Jun-Tao Cao,Wen-Sheng Zhang,Hui Wang,Shu-Hui Ma,Yan-Ming Liu
A novel fluorescence (FL) immunosensor for prostate-specific antigen (PSA) detection was developed based on the Förster resonance energy transfer (FRET) between nitrogen and sulfur co-doped carbon dot functionalized silica nanospheres (Si/NS-CDs) and Au@Ag NPs. The strategy utilized the PSA primary antibody labeled luminescent Si/NS-CDs as donors and PSA secondary antibody labeled Au@Ag NPs as acceptors. In the presence of PSA, the bio-affinity of the antigen and antibody caused the Si/NS-CDs and Au@Ag NPs to approach at a close enough distance for the FL intensity of the Si/NS-CDs to decline owing to the FRET effect. By virtue of the excellent optical properties of the Si/NS-CDs nanoprobe, the quantitative analysis of PSA has been successfully realized using both FL spectroscopy and a naked-eye readout. The fluorometric results present the desirable analytical performance for PSA detection in the range from 5.0 pg mL−1 to 10 ng mL−1 with a detection limit of 0.95 pg mL−1 (S/N = 3). Moreover, satisfactory results for the determination of the PSA target in samples of human serum were obtained, showing the great promise of the method for application in biochemical analysis.
研究领域:
生物化学
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医学诊断
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纳米技术
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DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 5
·1733
·
IF 3.748
Jinyu Zhang,Cai Jing,Binsong Wang
A signal shut-off probe of Si, N-codoped carbon quantum dots (Si, N-CQDs) was exploited to detect Cr(VI) by fluorescence quenching without the aid of any biomolecules or labeling materials. The sensing system prepared the precursor of diacetone acrylamide and the silane coupling agent 3-aminopropyltriethoxysilane (KH-550) by a simple hydrothermal method, and the quantum yield is as high as 75% Si, N-CQDs. The fluorescence stability and microstructure of the Si, N-CQDs were studied. The Si, N-CQDs has a high sensitivity for detecting Cr(VI) with the linear range of 0–200 μM and the detection limit of 0.995 μM. The quenching mechanism of Si, N-CQDs is attributed to FRET.Keywords:Si,N-codoped carbon quantum dots;hexavalent chromium;fluorescence sensor;mechanism attributed to FRET
研究领域:
分析化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）